1. Field of the Invention
This invention relates to the field of signaling systems, and in particular to a system which provides an audible response to a triggering event, a doorbell system being a nonlimiting example.
2. Brief Description of the Prior Art
Prior art doorbell systems are available in a variety of formats. A pushbutton on the outside of an entrance door wired to a mechanical or an electrical tone generator mounted somewhat centrally of a dwelling or a building remains the most popular format. Although both the electrical and mechanical versions may be provided to emit a single tone or multiple tones played in sequence, such devices are quite limited in their functionality.
For example, U.S. Pat. No. 4,326,276 to Scott, Jr. proposes an electronic tone generator which plays one of a repertoire of musical tunes when a door pushbutton is pressed. Different musical tunes may be selected by the occupant by means of a keyboard connected to a microprocessor. In addition to the playing of a tune when the door pushbutton is pressed, a built-in clock system displays the time of day and enunciates each quarter hour by means of musical notes.
U.S. Pat. Nos. 4,868,540 and 5,210,520 to Housley disclose a programmable doorbell system which displays messages and/or sounds a tone for the visitor pushing the doorbell pushbutton. A digital record/playback circuit may be provided to record an audible announcement by the occupant and stored as a digital signal. The audible announcement is generated from the stored digital signal when the doorbell pushbutton is pressed by a visitor. It is to be noted that these two patents to Housley relate to a programmable doorbell system for communicating visually or audibly to the visitor, and is not concerned with programming or playing recorded signals to the occupant upon the pushing of a doorbell pushbutton by a visitor.
U.S. Pat. No. 5,570,083 to Johnson discloses a doorbell answering system functionally similar to the Housley devices in which the occupant may select whether the system will energize the doorbell announcing the visitor or provide a prerecorded message for playback to the visitor. The doorbell and/or record modes are selected by the user by a switch located within an interior housing mounted adjacent a building entrance. Like the Housley devices, the Johnson system is not concerned with playing different audible messages to the occupant upon pushing of the doorbell pushbutton by a visitor.
U.S. Pat. No. 5,475,369 to Baker proposes a pet sounding device in which, upon physical contact of a wireless transmitter by the pet, sounds, chimes, or voice messages are emitted to alert the occupant that the pet wishes to either enter or exit the house or building. Sound variations are proposed for indicating the location of the actuated pet sensor.
U.S. Pat. No. 5,583,477 to Yen proposes a wireless AC/DC bell system in which an RF transmitter sends a triggering signal to a receiver for driving a speaker with an oscillating tone.
U.S. Pat. No. 5,564,294 to Chen discloses a musical door lock. When a pushbutton on the outer periphery of the door is pressed, a musical melody, or the sound of bird chirps will be emitted from the door lock housing. Chen also proposes a wireless coupling between the door lock arrangement and a movable wireless doorbell. The musical door lock is also proposed to be combined with an antiburglar device.
U.S. Pat. No. 5,365,214 to Angott et al. discloses a musical wireless alerting system in which the occupant is presented with a selection of a song or a melody dependent upon an audio code transmitted by a triggering device. A plurality of stored songs or tones within memory are selectable for transmission to a speaker which plays the tone or song upon initiation of the triggering device. The trigger device is proposed to be, for example, the pushing of a doorbell pushbutton or the opening of the door. Additionally, audible selection means are provided for manually selecting one of the plurality of audio codes representative of different audible indications produced by the audio means. That is, selection of the song or melody is made at the triggering device, and the receiver simply responds to the transmitted audio code from each triggering device to play the selection which the code represents.